基于岭估计的快速静态精密单点定位研究

The Research on the Fast Static Precise Point Position Based on Ridged Estimation

精密单点定位可以实现厘米级的定位精度,但其实时应用受到模糊度收敛时间的限制,模糊度收敛一般需要30分钟甚至更长的时间.基于相位历元间差分技术,可以避免模糊度的求解,但求解的参数为历元间坐标差.在相位历元间差分技术基础之上,推导了无模糊度模型的快速静态单点定位模型,并通过岭估计理论来进行参数的求解,两个以上历元就可以解算得到位置参数,从而实现静态状态下单点的快速定位,克服了模糊度收敛时间的局限,并讨论了不同坐标初值情况下估计值的精度.

Precise Point Positioning （PPP） has been reported to have a precision at centimeter level in static mode and at centimeter to decimeter level in kinematic mode. However, the application of PPP to real-time is still limited by its long convergence time, typically 30 minutes, which is necessary for the float carrier phase ambiguity resolution. The ambiguity free model of PPP can eliminate the initial phase ambiguities through epochdifference of phase observations. However, this mode only estimates coordinate differences between two sequential epochs. Therefore, the station coordinates need to be derived with additional methods, e.g., combined with noised range observations. In this paper, based on the phase epoch-difference, a fast static PPP algorithm is developed, where parameters estimarion is based on the ridged estimation. The coordinates can be estimated by observations only at two epochs, assuring the fast PPP. Using the 1 hour-data collected on the 295th day of 2007 in Tongji University, a test was carried out. Results show that the coordinate precision can be at centimeter to decimeter level when the initial values are different.